Igor Cassini, society and gossip columnist who had his own interview show on the Dumont TV network and early on proclaimed future first lady Jacqueline Kennedy as “debutante of the year,” in 1947, died Saturday Jan. 5 of natural causes in his Manhattan Home. He was 87.

He rose to prominence as society columnist for William Randolph Hearst’s New York Journal-American, writing under the name Cholly Knickerbocker. He is credited with coining the term “jet set” and helping spark a national fascination with Jacqueline Bouvier, future wife of John F. Kennedy. Later, when Jacqueline Kennedy was first lady, brother Oleg gained fame as her designer.

From 1953 to 1954, Igor Cassini had his own interview show on the now-defunct Dumont TV network.

He ran into trouble in the early 1960s, when an investigation by the Saturday Evening Post revealed he had served as a public relations agent for the Dominican Republic’s longtime dictator, Rafael Trujillo, without properly registering as a foreign agent. Trujillo was assassinated in 1961. The investigation caused Cassini to resign from his job as Knickerbocker.

Born in Russia, Cassini was the second son of an aristocratic family under the last czar. The family was forced to flee to Italy during the Russian Revolution.

Cassini and his brother later came to the United States, where they both became intrigued by Hollywood. Oleg Cassini first became established as a designer of costumes for the movies.

Columnist Liz Smith was a one-time employee and longtime friend of Igor.

He is survived by four children and his brother.